Abstract
We studied the structures formed in aqueous dispersions ofcharged colloidal spheres under a constant low salt concentration ofc = 6 × 10−6 mol l−1. Particlesof diameter 2a = 1000 nm were confined to a low angle wedge geometry with plate separation0<S<50 µm and observed with video microscopy. Irrespective of the initial particle densityn we reproducibly observe the particles to migrate to the narrow wedge side on thetimescale of a few days. Thereby an interface between a crystalline structure anda near particle free region is formed, which propagates slowly until the diluteregion is exhausted of particles. While the origin of this separation is still unclear,the final extension of the crystalline region is stable on the timescale of months.Within the crystal phase we observe a characteristic sequence of structures withincreasing plate separation similar to that seen in previous experiments on hardsphere-like systems but here with non-touching particles. Moreover, we find thatmechanical equilibrium is a necessary prerequisite for observing the full richness ofdifferent phases. A detailed comparison to recent theoretical calculations for bilayerswas performed and semi-quantitative agreement with the predictions observed.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
